I woldn't buy a desk, chair or couch from Ikea cheapest options, but I have some bookcases, shelves and so on. I like them because they're hackable[0] and price is also a factor. I have great desk and couch but my other furniture in "office" changes all the time - I buy some Lack, Expedit and Capita and build stuff. Angled shelves, messed bookcase, stands from drawers ...

[0] - http://www.ikeahackers.net/